<!DOCTYPE html>
<html>
<head>
<style type="text/css">
.box{
width:100px; height:100px;
background-color:red;
margin:10px; padding: 10px;

float:right;
}
</style>

<meta charset="EUC-KR">
<title>Insert title here</title>
</head>
<body>
<div class = "box">1</div>
<div class = "box">2</div>
<div class = "box" style = "clear: right;">3</div>
</body>
</html>